Explain effects of harmful substances in crop production

The effects of harmful substances such as pesticides, fertilizers and other chemicals in crop production have the following harmful effects:

1. Affects soil fertility when used in excess.

2. Crops produced with the help of such fertilizers are harmful for consumption as it can enter our system and cause several abnormalities.

3. These chemicals can get washed away with water and get mixed with water bodies resulting in water pollution.

4. Such chemicals are also harmful to the farmers who apply it in the fields.

its d i know cause i've been googling it